/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2008-2011, Salzburg Research. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * - Neither the name of the KiWi Project nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Contributor(s):
 * sschaffe
 *
 * File Info:
 * User: sschaffe
 * Date: 2011/01/03
 * Time: 16:42
 *
 * Project: KiWi2, kiwi-core module
 */

package kiwi.core.api.transaction;

/**
 * Add file description here!
 * <p/>
 * User: sschaffe
 */
public interface TransactionService {



    /**
     * Get the transaction that is active in the current thread. Each thread may only have a single active transaction.
     * If no transaction is associated, a new transaction is created and associated with the thread.
     * @return
     */
    public Transaction getTransaction();


    /**
     * Get the transaction with the id given as argument. The method is useful for long-running transactions
     * that span more than one request. In this case, each request must pass on the transaction id to retrieve it.
     * <p/>
     * Each thread may only have a single active transaction.
     * <p/>
     * If no transaction is associated with the thread and the transaction with the given id is already managed
     * by the TransactionService, the transaction is associated with the current thread.
     * <p/>
     * If there is already another transaction associated with the thread, a ConcurrentTransactionException is thrown.
     * <p/>
     * If there is no transaction with the given id, a NoSuchTransactionException is thrown.
     *
     * TODO: check that it is not associated with a different thread!
     *
     * @param id
     * @return
     */
    public Transaction getTransaction(String id);


    /**
     * Add a transaction dependency to the transaction that is active in the current thread. A transaction dependency
     * means that the current transaction will not commit before all dependencies are committed successfully.
     * @param transactionId
     */
    public void addTransactionDependency(String transactionId);


    /**
     * Begin a transaction. The method simply modifies the state from CREATED to ACTIVE and is used as an indicator
     * for the developer.
     *
     * @param t
     */
    public void begin(Transaction t);


    /**
      * Commit the transaction passed as argument. Takes the data that is in the transaction and stores it to the
      * database.
      *
       * @param t
      */
    public void commit(Transaction t);


    /**
     * Rollback all changes done to the KiWi system in the transaction passed as argument. Will remove all elements
     * that have been added to the caches and undo all modifications done to triples, resources and namespaces.
     *
     *
     * @param t
     */
    public void rollback(Transaction t);


    /**
     * Abort the transaction passed as argument. Changes the state of the transaction to aborted.
     * @param t
     */
    public void abort(Transaction t);


    /**
     * Disassociate the current transaction from the current thread; needed for long-running transactions.
     */
    public void freeTransaction();

}
